The collection of a biological fluid sample (blood, saliva, urine, etc) from a patient is the first step in many diagnostic procedures. Pre-evacuated collection tubes designed for venous collection of blood samples are commonly used devices, and several companies sell a broad portfolio of blood collection tubes pre-filled with additives like Heparin, EDTA, and nucleic acid stabilization agents to facilitate downstream testing processes. Problems associated with venous collection products are the requirement for trained individuals to assist the patient in the collection of the sample, risks associated with puncturing a vein with a needle, and the collection of substantially more patient sample than is needed to perform a diagnostic test.
Capillary tube based collection devices are used to collect a small volume of blood from a patient's fingertip or heel. These devices usually function by holding the tip of an open end capillary tube against the drop of fluid and the fluid is then drawn into the tube using capillary forces. Alternative collection methods include dripping of a patient's sample onto a piece of paper or into a collection container. Microneedle based evacuated devices are also in development. Similar to evacuated tubes, these devices are often coated with additives to facilitate future diagnostic testing or improved sample handling. In some instances, the biological fluid is dispensed into a secondary container when it can be mixed with additive and/or stored until later use.
Furthermore, there is a growing demand for blood samples for molecular diagnostic tests that require immediate stabilization of the genomic material at the time of collection. Proper stabilization usually requires immediate mixing of the blood with a stabilization buffer within a defined ratio of blood to buffer. Current devices are not designed for this application.
Given the above background, there is a need in the art for collection devices and methods that enable simplified collection of biological samples and facility the mixing of the biological samples with additives that aid in the stabilization and future processing of the samples.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.